The Biostatistics Data Management Core will provide comprehensive support for the data acquisition, data-management, experimental design and statistical analysis of each clinical science and basic science project and other cores of this program project. Biostatistical scientific collaboration will enhance each project by incorporating efficient statistical designs, and through prospective data collection and quality control procedures. We will facilitate project management through integrated data base development with web-based access, by delivering planned and tailored statistical analyses for rapid communication of project results among project investigators, and by collaborating with all project investigators to facilitate the timely publication of scientific results. The aims of the Biostatistics Core are: To provide the statistical design for each project. To provide prospective data collection, data entry, and quality control of data for the clinical trial. To develop a web-based database which will contain both clinical and biomarker data from all projects. To provide all statistical data analysis including descriptive statistical analysis, hypothesis testing, estimation, modeling of prospectively generated data. To generate statistical reports for all projects. To develop and adapt statistical methods to effectively analyze multiple biomarker data measured over time in lung cancer chemoprevention research. To collaborate and assist all project investigators in the publication of scientific results.